The present invention relates to protease enzymes for tough cleaning and/or spot and film reduction in various compositions and methods for their use, more particularly to protease enzymes which are carbonyl hydrolase variants.
Various types of enzymes have long been used in laundry detergents to assist in the removal of certain stains from fabrics. Each class of enzyme (amylase, protease, etc.) generally catalyzes a different chemical reaction. For example, protease enzymes are known for their ability to hydrolyze (break down a compound into two or more simpler compounds) other proteins. This ability has been taken advantage of through the incorporation of naturally occurring or engineered protease enzymes to laundry detergent compositions.
In recent years the use of enzymes has also been investigated for use in automatic dishwashing compositions. Unfortunately, many enzymes, especially protease enzymes, do not translate well into the wash environment. Specifically, thermal stability, pH stability, oxidative stability and substrate specificity need to be optimized to ensure satisfactory performance.
To optimize the characteristics of the protease enzyme, a change in the amino acid sequence is frequently employed. A change of amino acid sequence may alter the properties of the enzyme to varying degrees depending upon the location, nature, and/or magnitude of the change in the amino acid sequence. Several attempts have been made to alter the amino acid sequence of protease enzymes in an attempt to alter their properties, with the goal of increasing the efficacy of the protease for cleaning uses such as in the wash environment.
Additionally, consumers interest in automatic dishwashing compositions which deliver tough food cleaning is increasing. Baked on dairy products and eggs have long been difficult to remove via automatic dishwashing. In addition, spotting and filming of glassware is a common problem in autodishwashing. Moreover, consumers now desire less handwashing or pre-washing of dishes and more cleaning ability delivered via the automatic dishwasher. Accordingly, the need remains for compositions which can deliver tough cleaning and/or spot and film reduction cleaning without spot/film formation. More particularly, the need remains for automatic dishwashing compositions which can deliver tough food cleaning and reduced spot/film formation via protease enzymes designed to deliver such benefits.
The following documents contain information which may or may not be relevant to the present invention:
WO 95/10615 to Genencor International, Inc.; WO 89/06270 to Novo Nordisk A/S; Kirk-Othmer, Encyclopedia of Chemical Technology, 4th. Ed., Vol. 9, Wiley 1994, pages 567-620, titled xe2x80x9cEnzyme Applications-Industrialxe2x80x9d, Nielsen et al and the references therein. WO 95/10591 and WO 95/10592 to the Procter and Gamble Company.
This need is met via the present invention whereby compositions having a protease enzyme capable of tough food cleaning and reduced spotting/filming is provided. The preferred protease enzyme is a carbonyl hydrolase variant having an amino acid sequence not found in nature. The protease is engineered to deliver tough cleaning and/or spot and film reduction and reduced spotting and filming by providing the protease with trypsin-like specificity. Thus, the protease is highly effective on dairy soils such as milk and cheese and on egg yolk soils and significantly reduces the spotting and filming such soils may cause in the automatic dishwashing process. The protease is derived by replacement of a plurality of amino acid residues of a precursor carbonyl hydrolase with different amino acids. Furthermore, the preferred protease is engineered to have a higher level of bleach stability. In addition, the enzymes of the present invention may provide improved soil removal in laundry applications as well.
According to a first embodiment of the present invention, a cleaning composition is provided. The cleaning composition comprises:
(a) an effective amount of a protease enzyme which is a carbonyl hydrolase variant having an amino acid sequence not found in nature, which is derived by replacement of a plurality of amino acid residues of a precursor carbonyl hydrolase with different amino acids, wherein said plurality of amino acid residues replaced in the precursor enzyme correspond to position +210 in combination with one or more of the following residues: +33, +62, +67, +76, +100, +101, +103, +104, +107, +128, +129, +130, +132, +135, +156, +158, +164, +166, +167, +170, +209, +215, +217, +218 and +222, where the numbered positions correspond to naturally-occurring subtilisin from Bacillus amyloliquefaciens or to equivalent amino acid residues in other carbonyl hydrolases or subtilisins (such as Bacillus lentus subtilisin); and
(b) one or more cleaning adjunct materials compatible with the protease enzyme.
Most preferably, the protease is derived by replacement of a plurality of amino acid residues of a precursor carbonyl hydrolase with different amino acids, wherein the plurality of amino acid residues replaced in the precursor enzyme correspond to position +210 in combination with one or more of the following residues: +76, +103, +104, +156, +166, and +217, +222, and most preferably, the protease is derived from replacing amino acid residues at positions +210, +76, +103, +104, +156, and +166.
The present invention also relates to methods for cleaning items in need of cleaning by contacting the item with a protease enzyme which is a carbonyl hydrolase variant as described herein. The invention therefore encompasses a method for cleaning fabrics comprising contacting, preferably with agitation, the fabrics with an aqueous liquor containing the protease enzyme. The method can be carried out at temperatures below about 60xc2x0 C. but, of course, is quite effective at laundry temperatures up to the boil. The present invention also relates to a method for cleaning dishes by contacting a dish in need of cleaning with a protease enzyme as described herein. The present invention methods also include methods for personal cleansing, the methods comprising contacting the part of the human or lower animal body in need of cleaning with a protease enzyme as described herein.
Accordingly, it is an object of the present invention to provide a cleaning composition having a protease enzyme capable of tough cleaning, and/or spot and film reduction particularly an automatic dishwashing composition having tough soil or food cleaning. It is further an object of the present invention to provide methods for fabric, dish and personal cleansing via the use of the protease enzymes of the present invention. These, and other, objects, features and advantages will be clear from the following detailed description, the attached drawings and the appended claims.
All percentages, ratios and proportions herein are on a weight basis unless otherwise indicated. All documents cited herein are hereby incorporated by reference.